Refrigeration



I Oct. 9, 1945. g, Q CQQNS REFRIGERATiON Filed Feb. 25, 1942 I 2 Sheets-Sheet 1 Q 8 &

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t- 9, 5- c. c. COONS REFRIGERATION med Feb. 25 1942 2 Sheets-sheaf w wk 8 mm e V 6 w m C ATTORNEY Patented-Oct. 9, i945 UNITED STATES PATENT asscsas' Q F E;

nnraroaas'rron Curtis C. Coons, North Canton, Ohio, assignor to -The Hoover-Company, North Canton, Ohio, a

corporation of Ohio Application February 25, 1942, Serial No. 432,207

' 20 Claims. (01. 62-5) 1 This invention relates to refrigeration and more particularly to an arrangement whereby an absorption refrigerating apparatus can be assembled with a domestic refrigerator cabinet with the top of the evaporator at' a higher level than the bottom of the condenser, thus reducing the total height of the apparatus and rendering a larger proportion of the cabinet space available.

tioned in the food storage compartment. In the" absorption refrigerating field, however, the problem is more difficult because the parts usually must be located in definite locations relative to each other insofar as vertical height is concerned. Thus anything which will reduce the total vertical height of the apparatus will be advantageous.

According to this invention the vapor flowing from the generator to the condenser is utilized to raise refrigerant liquid from the condenser to a higher level from where it can flow by gravity into the top of the evaporator. IBy this arrangement it is possible toposition the condenser at Other objects and advantages of this invention will become apparent as the description proceeds when taken in connection with the accompanying drawings in which:

Figure 1 is a diagrammatic representation of a dual intermittent absorption refrigerating machine with thisinvention applied thereto;

Figure 2. is a diagrammatic representation of a single intermittent absorption refrigerating the same level or below the evaporator making it unnecessary to position the entire' condenser above the evaporator and to this increase the This renders it total height of the apparatus. possible to make the total cabinet height smaller for a particular food storage'capacity or to reduce thespace occupied bythe apparatus and increase the food storage capacity.

More specifically, according to this invention,

- the vapor from the generator-flowing to the con-- denser'is passed into liquid refrigerant from the condenser so as to form a vapor lift pump which raises the liquid refrigerant to a vapor separation chamber above the top of the condenser and the evaporator wherein the vapor is separated from the liquid and flows to the condenser whileplication but can be applied to other types of absorption refrigeration machines as well.

machine with this invention applied thereto; and

Figure 3 shows the parts of the machine of Figure l properly arranged and assembled with a standard domestic refrigerator cabinet.

Referring to Figure 1 of the drawings, A, A

represent two generator-absorbers, C, C two primary condensers and E, E two evaporators. The absorbent receiving space of the generatorabsorbers A, A are connected to the condensers C, C by conduits I0, III and conduits II, II, the latter forming. vapor lift pumps whose operation will be described more particularly hereinafter. The-conduits I I, I I open at their upper. ends into vapor separation chambers I2, I2, the vapor space of which is in open communication with the top of the condensers C, C. The condensers C, C have a downwardly inclined slope through: out and are connected by liquid traps l3, I3 to the junction of conduits I0, I0 and II, II'. The bottomsof the vapor separation chambers I2, I2 are connected by conduits I4, I4 which include liquid traps I5, I5 to receiving vessels I6, I6 which form a part of the evaporators E, E. In actual practice the traps l5, I5 should be embedded in insulation for a purpose to be described hereinafter. The insulation has not been shown in the drawings, so that the parts of the apparatus will be more readily visible.

Each generator-absorber A, A has an absorbent receiving chamber formed by the, outer cylindrical walls of vessels A, A, the outer cylindrical walls of'the heat exchange vessels l8, I8 and of the annular chambers.

'any well known solid absorbent such as strontium manner well known to the art.

end closures (not shown) welded to the cylindrical walls. The annular chambers so formed. are

provided with suitable trays (not shown) having openings through the walls thereof and being welded to the inner and outer cylindrical walls These trays support chloride which will absorb the refrigerant vapor such as ammonia, which solid absorbent maybe charged into the absorption chambers in any 'I'he'heat exchange vessels I8, I8'are formed of inner and outer concentric cylindrical walls detail hereinafter.

an annular receiving chamber for .an indirect cooling fluid of the indirect coolingcircuit for the generator-absorbers A', A, the construction and operation of which. will be described in more In the cylindrical space formed by the inner cylindrical walls of the heat exchange vessels l8, l8 are electric heating cartridges 20, of any suitable construction known to the art. I

The upper end ofeach of the annular heat exchange chambers of the generator-absorbers A,

,A is connected by conduits 84, 84' to the secondarycondensers' 86, 86'. The secondary condens- 2f f N I a,ase,4se

ers 86, '86 have a continuous downward slope U throughout and lead to a reservoir 88. The reservoir 38 is connected by a conduit to a valve chamber 42. The valve chamber 42 is connected by conduits 44, 44 to the lower end of the annular heat exchange vessels l8; l8 for the generator-absorbers A, A. The valves: 48, 40' are absorbers A, A which are formedv bythe heat exchange vessels l8, l8, conduits, 84', secondary condensers 86, 88', storage vessel 88, conduit 48, valve chamber 42 and conduits 44, 44', is suitably charged with avaporizable liquid'such as methylchloride. The pressure within the indirect cooling circuit is not high so that the snap acting device 48 may be led into the interior of the valve chamber 42 through a suitable flexible joint 18,

The refrigerating apparatus just described and shown diagrammatically in Figurel is adapted to be arranged so as to be mounted in a domestic refrigerator cabinet asshown in Figure 8. The

cabinet comprises a back insulated wall 88, lower insulated wall 82,1 front access door 84 and top insulated wall 86.- Atthe rear .of the cabinet is the points of connection of the conduits 88,.88'.

The conduits 8|, ii are in thermal contact with an icefreezing chamber 84, while the conduits 52, 52' have heat exchange fins thereon forbox cooling purposes. The operation of the evaporators E, E will be described in more detail heresurfaces of generator-absorbers A, A and are connected by capillary tubes 58, 88' to bellows 88v 60'. which upon expansion and contraction are adaptedto operate the snap acting device 48. The bulbs 58, I58, tubes 58, 88' and bellows 80, 80' 'are filled with a suitable vaporizable fluid sov that the bellows 80, 80' will expand and contract upon variations in temperature of the bulbs 88, 58' as is well known in the art. A snap acting switch 82 of any well known construction is positioned to be actuated by the snap acting device 48. i

A thermostatic bulb 84 is positioned in conta with the ice freezing vessel 84 and is responsive to the temperature of that vessel. The -.bulb I4 is connected by a capillary tube 68 too bellows 68.. The bulb 64, tube 86 and bellows 88 are filled withsuitable vaporizable fluid so that. the bellows at will expand and contract upon-variations in temperature of the ice freenng, chamberv 84 asis wellknown' in the art. Thebellows'".

upon expansion and contraction, is adapted to actuate a snap-acting device II which in turn operates the valve 12 in the conduit 48, and an electric switch I4. One side of the power line is connecte'dto one side of the switch 14. The other side of the switch I4- is connected by's'uitable conductors provided a, flue 88 for the. circulation of air over the heat rejecting parts of the apparatus. An

opening "at the bottom of the flue 88 provides as notto interfere withfthe air circulation. The primary condensers C, C extend across the flue 88 near its upper end and substantially atthe same height. as the evaporators E, E and the secondary condensers 88. 88" are similarly arevaporator is adapted to pass when the apparatus is assembled with the cabinet. An insulating 8 -ket 88 is'provided for sealingthe space between the closure 84 and the opening in the back of the cabinet. 5 l

As shown in Figure 1 the valve 12 isopenand the switch is closed. The switch 82 is set so that electricit will be conducted to the heating cartridge 20 of the generator-absorber A which will be heated. The bulb to is contracted and the bulb 'v is expanded by a previous heating of the generator-absorber A as will be described herepass by the conduit l0 and conduit II to the condenser C where it will condense and the heat of condensation will be carried away by air flowing over the heat rejecting tins mounted upon the tubes of the condenser.

When sufllcient refrigerant vapor has con- 1 densed in the condenser to till the trap I! up tothrough the conduit H and will beraised into as shown to two of .the contacts ofthe switch- 82. The other'two contacts of the switch 82' are connected by suitable conductors to one side .01 thekelectricheating cartridges 2., a, the de elf-which is connected to the other side of the the junction of the conduits III and ll,'slugsof this-condensed, refrigerant will be trapped be?" tween slugs of refrigerant vapor flowing upwardly the-vapor separation chamber l2; In the vapor separation chamber l2 the vapor will separate from the liquid refrigerant and pass to the upper end of the condenser C'where it is condensed and flows into the trap II to beraised into the vapor separation chamber l2 as. previously described in connection with the first refrigerant vapor enterlng the condenser C. 1

.Theliquld' refrigerant will collect in the bottom of the vapor separation chamber l2 and flow through conduit l4 to the collecting vessel It by gravity flow. The liquid trap II is provided to prevent vapor from the vapor separation chamber from; entering; the'collecting vessel ii. The liquid-refrigerant entering the collecting vessel It will'flll the conduits, SI and 52 as well'as the collecting vessel itself. v

During the heating of the generator-absorber A the auxiliary cooling liquid in the annular heat exchange, chamber l8' of the generatorabsorber A-will quickly vaporize and flow by conduit 34 into the secondary condenser 36. The air flowing over the fins of the condenser 36 will .carry away the heat of condensation of the auxiliary fluid wherebyit will condense and'flow 3 herebe pointed out that the liquid refrigerant contained ln the liquidtrap l5 must first evap-' orate. The traps l 5; II are preferably insulated so that the evaporation of'the liquid refrigerant therein will not condense moisture on the tubes formingthe traps. v

As'absorption proceeds in the generator-absorber A, the heat '0! absorption is transferred to theauxiliary cooling liquid in the annular heat exchange chamber 18. This vaporizes the auxiliary liquidand this vapor flows to the condenser by conduit 34. Herev the vapor is condownwardly through the tubes of the condenser 36 into the reservoir 38. This liquid auxiliary cooling fluid cannot return to' the generatordensed and the heat of condensation carried away by air flowing over the heat rejecting flns of the condenser 36. The tubes ofthe condenser 36 have a continuous downward slope and theliquid absorber A at this time because the valve 46 is closed. Y

In the meantime absorption of refrigerant vapor is taking. place inthe generator-absorber A in a manner which will be described in connection with the absorption which takes place in the generator-absorber A when the control operates' to shift the generator-absorber Ajfrom the generating phase to the absorption phase and the generator-absorber A from the absorption phase to the generating phase.

When'suflicient refrigerant is driven from the absorbent in the generator-absorber A the heat from the'heating cartridge will no longer be utilized in evolving refrigerant vapor from the.

absorbent in the generator-absorber A and it will auxiliary cooling fluid returns to the reservoir 38 to be returned in due course to the annular heat exchanger chamber i8 for furthercooling action.

The refrigerant which is evaporating in the evaporator E at this time will cool the conduits 50, 5| and 52 which will in turn cool theice freezing chamber 54 and freeze the contents thereofas well as cool the air in the refrigerator com partment or food'storage space. Since the conduit 50 is insulated no evaporation will take place therein. .The conduit 5| being in contact with rise in temperature. This rise in temperature will refrigerant is vaporized the heat supplied quickly raises the temperature of the generator-absorber toa much higher value. i v

This will cause the liquid in the bulb 56 to vaporize whereby the bellows 60 will be expanded. At thistirne the bellows 50' will be in contracted position because absorption istaking place in the generator-absorber A and the fluid in the bulb 56' will be condensed. Expansion of the bellows 60 will push the snap acting device 48 to the right which will operate the switch 62 to deenergize the heating element 20 and to energize the heating element 2 0'. At the very same time it will operate to open the valve 46 and to close the valve 46'. t

Theindirect cooling system is charged with suflicient auxiliary cooling medium that the reservoir 38, will always contain auxiliary cooling time the auxiliary cooling liquidwill be quickly vaporized by the transfer-of heat-of vaporization of the auxiliary liquid from the generator absorber A- and it'will thus be quickly cooled.

' The cooling of the generator-absorber A will the freezing chamber 54 and the conduit52 being in heat exchange with the air in the food storage compartment, a comparatively rapid evaporation of liquid refrigerant will take place therein. i

This will cause the liquid in conduits 5| and 52 to be raised upwardly so that a positive ci-iculation of the liquid refrigerant will take place.

Thiswillaugment the cooling effect of the evap- As the evaporation and absorber A. the generator-absorber A" is being heated by the heating element 20. Vapor isjbe; ing driven from the solid absorbent in the generator-absorber 'A", condensed in the condenser C and collected in the evaporator E as pree viously described in connection with the evolutionof vapor from the generator-absorber A.

By the time that substantiallyall the liquid refrigerant in the evaporator E has evaporated the refrigerant vapor will be driven from the solid absorbent in the generator-absorber A. This will cause the medium in the bulb 56' to expand the bellows 60 in the manner previously described in connection with the generator-absorber A. The snap acting device 48 will be moved to the left as viewed in Figure 1 whereby the valve 48 will be closed, thevalve 46' opened tridge 20". This will cause vaporization to take place in the generator-absorber A and absorption in the generator-absorber A which will proceed as previously described. a

The frozen ice in the ice freezing chamber 54 will act as a cold hold over'device and will cooperat'e with the evaporation takingplace in-one I evaporator while hot refrigerant is being supplied to the other to hold the temperature 01 the food reduce the vapor pressure therein andv the solid in the evaporator IE will begin.

The refrigerant vapor evaporating in the evapstorage space substantially constant.

The control will function to operate alternately the generator-absorbers A, A on the generating period and on abgorption period as just described I until the temperature or the ice freezing chamber orator E will return to the generator-absorber A by conduit I4, liquid trap l5, vapor separation l2, conduit Ii and conduit Hi. It may the bulb 6E willoperate to collapse the bellows 68 chamber 54 goes below a predetermined limit which is very substantiallybelow the temperature of the air in the food storage compartment. At that time absorption is taking 1' 4 place .in the evaporator E and 'the generator-=1" Figure 1.

and operate to close the valve "ll-and open the switch 14. This will operate to de-energize that generator-absorber which is then being energized and to stop the'flow of cooling fluid in the indirect cooling circuit.

The liquid cooling medium in theannular heat absorbent the generator-absorber its temperature will quickly rise as described in con-' nection with Figure 1 and the bellows III will expand to move the snap acting device 48 to the right which will open the valve 46 as well as the snap acting switch 82 so that the heating element 20 is de-energized.

The opening of the valve. 46 will cause the liquid cooling medium in the reservoir 38 to be the cooling space of the generator-absorber being i cooled, but will flow to the reservoir 38' and be.

trapped out of the circuit by the closed valve 12. When the absorption of refrigerant vapor in the generator-absorber being cooled ceases, no more liquid refrigerant will evaporate in the evaporator of that unit. Thereafter the temperature of the air in the food storage compartment and consequently the temperature of the freezing chamber 54 will slowly rise until the control bulb 8 8 again acts to open the valve 12 and close the switch H. The two units will then operate cyclicly as previously described. v

This invention can be applied to a single intermittently operating absorption unit of the general type disclosed in connection with Figures 1 and 3. Figure 2 shows such a modification.

The same reference characters will be applied dumped into the annular heat exchange, chamher it of the generator-absorber A so that it will be quickly cooled as described in connection with the modification of Figure 1. This will cause the vapor' pressure in the generator-absorber A to be reduced and absorption of refrigerant vapor will take place therein and evaporation of the liquid refrigerant in the evaporator E in the same way as described in connection with the modification or Figure 1,'until allof the liquid ref-rigerant in the evaporator E has been absorbed in the generator-absorber A.

When this occurs absorption will cease in the generator-absorber A with theflresult that no to Figure-2 as applied to Figures 1 and 3 insofar as they apply. The generator-absorber A is charged with strontium chloride as the absorbent and ammonia as the refrigerant and the indirect cooling system is. charged with methyl chloride as in the modification of Figure'l. The bellows 60 is connected to the snap acting device 48 by a lost motion connection and the switch 62 is modifled in that it has only two contacts. One contact of the switch is connected to one side of the power line, the ther to one side of the heating element 20. The other side of the heating element 20 is connected to the other side of the power line. One of the valves of the valve chamber 42 as shown in Figure 1 is omitted, leaving only the valve which controls the opening to the conduit 44. The snap acting device 48' and the bellows B0 are so adjusted that the snap acting device 48 will be snapped to a position opposite that shown in Figure 2 by thehi'gh temperature resulting. at the end of the generating phase of the generatorabsorber A as described in connection with Figure 1 but will not be snapped to the position shown in Figure 2 until the bulb 56 has reached the highest room temperature likely to be encountered, for a purpose to be described hereinafter.

In Figure 2 the evaporator shown in Figure 1 has been combined into a single evaporator so that the water freezing chamber 54 will act as a cold hold over in a manner similar to that of In this case the evaporator will have two conduits 50, two conduits 5i and two conduits 52.

more heat will be generated therein and its temp'erature will be lowered to substantially room temperature by the circulating cooling medium. This will cause the fluidln the bulb 56 to contractsufllciently to collapse the bellows 60 and to shift the snap acting device 48 back to the left as shown in Figure 2. The generator-absorber A will thus automatically operate alternately on the absorption and generating phases as the temperature thereof rises and falls without the necessity of providing any additional control. However, it is preferable that a control like that shown in Figure 1 be provided. Thus when the temperature of the ice freezing chamber 54 is lowered to a predetermined degree by the production of refrigeration in the vaporator'E, the

until the temperature of the food storage chamber rises sufhciently to raise the temperature of the ice freezing chamber to expand the fluid in the bulb 64 suihciently to operate the snap act- I'll).

' duction of a more compact arrangement of the As shown in Figure 2 the bellows 6B is contracted and the snap acting device 48 is positioned to the left so that the valve in the chamber 42 is closed as is the snap actingswitch 62.

The generator-absorber A will be on the generating phase and vapor being evolved therefrom is condensed and raised to the vapor separation chamber l2 from whence it will flow to the evaporator E as in the modification of Figure l.

. When the refrigerant vapor is driven from the parts of the apparatus insofar as vertical height is concerned. This renders it possible to assemble the unit with a domestic refrigerator cabinet so that a greater part of the cabinet space can be utilized for food-storage purposes for any particular capacity unit.

While I have shown but a number of embodiments of my invention it is to be understood that these embodiments-are to be taken as illustrative only and not in a limiting sense. I do not wish to be limited to the particular structure shown and described but to include all equivalent variations thereof except as limited by the scope of the claims.

I claim:

1. A refrigerating apparatus comprising a generator-absorber charged with a refrigerant and fying'means to a higher level; 1

,2. An absorption refrigerating apparatus comprising a generator charged with a refrigerantgenerator-absorber to evolverefrigerant vapor a.

from the absorbent, means for liquefyingat least a portion of said refrigerant vapor and means for, passing refrigerant vapor directly fom said for raising the liquid refrigerant from and absorbent, therefor, means forFbeating generator to evolve,irefrige antlm nfrom th e s e o d s m arondmtz said refrigerant vapor ,fromj' said-.1861

"erator to, said condenser, a, portion of-said conduit being constructedand arranged tofreceive conliquefied refrigerant in said place of evaporation and absorbing-the evaporated refrigerant in said place of evolution,

'- .7. That method of operating an absorption regenerator-absorber into said liquid refrigerant said liqueplace of condensation at another level, liquefying frigerating apparatus which comprises, evolving refrigerant vapor from absorbent in a place of evolution atone level, flowing said vapor to a the refrigerant vapor in said place of condensadensed refrigerant fromfsaidcondenser andva- V arranged that said refrigerant vapor will'raise the condensed refrigerant to a'higher level.

3. An absorption refrigerating apparatus comgenerator to evolve refrigerant vapor from said absorbent, a condenser, 'an evaporator, a conduit- -por from said generator, the-apparatus being so ition, passing the vapor flowing to said place of condensation into the liquefied refrigerant, utilizing the vapor for moving-the liquefied refrigerant to a place of evaporation, evaporating the liquid refrigerant in said place of evaporation, absorbing the evaporated refrigerant into the absorbent in the place of evolution and controlling the reversal from evolution toabsorption by the temperature of the place of evolution.

8. That method of operating an absorption refrigerating apparatus of the type having two places of evolution and absorption, two places of condensation and two places of evaporation which including a vapor separation chamber above the bottom of said condenser for leading said refrigerantvapor from said generator to said condenser, said conduit being constructed and arranged to receive liquid refrigerant from said condenser and refrigerant vapor from said generator, the apparatus being so arranged that the refrigerant vapor flowing toward said condenser will raise. said liquid refrigerant to said vapor separationchamber and means for leading said liquid refrigerant from said vapor separation chamber to said evaporator by gravity. 4. In combination, a domestic refrigerator cabinet, an absorption refrigerating apparatus associated therewith including a generator, a

-c ondenser above said generator and an evaporator above the bottom ,of said condenser, means for leading refrigerant vapor from said generator to said condenser, said means including a'conduit so constructed and arranged'as to receive liquidfrom said condenser and vapor from said generator, the apparatus being so arranged that the. vapor flowing to said condenser will raise the liquid from the condenser to a level from which it will flow by gravity to said evaporator.

\ 5. An absorption refrigerating apparatus comprising a generator charged with a refrigerant condenser and to utilize vapor flowing to said condenser for raising said liquid refrigerant to said :vapor separation chamber and means for ffleading said liquid refrigerant from said vapor separation chamber to said evaporator by gravity.

(:0. met methodof operating an absorption rerefrigerantvaporfrom absorbent in-a place of 1 evolution at one level, flowing, said vapor to a place of condensation atanother level, liquefying the refrigerant vapor in said place of condensacondensation into the liquefied refrigerant. utilizing the vapor for moving the liquefied refrigthe erant to a place of evaporation, evaporating apparatus which comprises, evolving comprises, evolving refrigerant vapor, from an absorbent in one place'of evolution and absorption, passing the refrigerant vapor to the first place of condensation, liquefying the vapor in the first place of condensation, passing the vapor flowing to the first place of condensation into liquid refrigerant fromthe first place of condnsation, utilizing .the vapor to move the liquid refrigerant to the first place of evaporation, evaporating the liquid refrigerant in said first place of evaporation, absorbing the evaporated refrigerant into the absorbent in the first place of evolution and absorption, said evaporation step 7 being carried out while evolution and liquefaction is taking place in the second places of evolution and absorption, and condensation, and controlthe temperature ofthe place of absorption in which evolution is taking place.

9. In combination, a domestic refrigerator cabinet having a food storage compartment and an apparatus compartment incluing an air fine, a

- I condenser in said apparatus compartment, the

tion', passing the vapor'flowing to said place of --nected to the top of said condenser, said vapor I lift pump being so constructed and arranged as top of said. evaporator being positioned at a higher level than the bottom of said condenser, a conduit for leading refrigerant vapor from said generator-absorber to said condenser, said conduit including a. vapor lift pump constructed to receive liquid refrigerant from the bottom of said condenser and vapor from said generator-absorber, the arrangement being such that the vapor from the generator-absorber raises lique fled refrigerant from the bottom of thecondenser to the top of said evaporator. r

10. In combination, a domestic refrigerator cabinethaving a food storage compartment and an'apparatus compartment including an air flue,

a refrigerating apparatus associated wlthsaid cabinet including an evaporator in said food storage compartment, a; generator-absorber and a condenser in said apparatus compartment, the 1 top or .said evaporator being positioned at a higher level than the bottom of said'condenser, a conduit for leading refrigerant vapor from said generator-absorber to said condenser, said conduit including a-vapor lift pump and a vapor separating chamber with its vapor space contoreceive liquid from the bottom of said conduit being constructed and arranged to receive condensed refrigerant; from said condenser and vapor from said generatonthe apparatus being so arranged that said refrigerant vapor will raise to a place of condensation, liquefying vapor in ing said generator to evolve refrigerant vapor from the absorbent, a condenser, an evaporator, conduit means including a vapor separation chamber above the bottom of said condenser for leading vapor evolved from the absorbent in the generator to said condenser, said conduit means also including a vapor lift pump constructed to receive liquid refrigerant from said condenser and to utilize vapor flowing to said condenser for raising the liquid refrigerant condensed in the condenser to the vapor separation chamber wherein the vapor ias'eparated fromv the liquid refrigerant and fiows to .said' condenser. ,and means for leading the liquid refrigerantfroni the vapor separation chamber to said evaporator .in-

cm fiow'-' eluding means for preventing vapo ing to the evaporator.

13. A refrigerating, apparatus comprising a generator-absorber charged with a refrigerant and an absorbent therefor, means for. heating said generator-absorber to evolve refrigerant vapor from the absorbent, means forliqnefying at least a. portion of said refrigerant vapor,

means for passing refrigerant vapor'ldirectly from said generator-absorber into, said liquid refrigerant for, raising the liquid refrigerant from said liquefying means to a higher level and means for leading the vapor passed into the liquid refrigerant to said liquefying means.

l4. An absorption .refrigeratlng apparatus comprising a generator charged with a refrigerant and an absorbent therefor, means for heating said generator to evolve refrigerant vapor from the absorbent, means for'liquefying at least a portion of said refrigerant vapor, means for passing-refrigerant vapor directly from said gener'ator into said liquefied refrigerant for raising the liquefied refrigerant from said liquefying means to a higher level and means for leading the vapor passed into theliquid refrigerant to said liquefying means.

15. An absorption refrigerating apparatus comprising a generator charged with a refrigerant and an absorbent therefor, means for heating said generator to evolve refrigerant vapor from theabsorbent, a condenser, a conduit for leading said refrigerant vapor from said generator to said condenser, a portion of said conthe condensed refrigerant'to a higher level and the vapor used to raise theliquid refrigerant to said condenser is conducted to said condenser.

16. An absorption refrigerating apparatus comprising a generator charged with a refrigerant and an absorbent therefor, means for heating said generator to evolve refrigerant vapor from saidabsorbent, a condenser; an evaporator, a conduit including a vapor separation chamber above the bottom of said condenser for leading said refrigerant vapor from said generator to said condenser, said conduit being'constructed and arranged to receive liquid refrigerant from said condenser and refrigerant vapor from said generator, the apparatus being scanned that the refrigerant vapor flowing to said condenser ,will raise said liquid refrigerant to said vapor separation chamber, and means for leading said liquid refrigerant from said vapor separation chamber to said evaporator by gravity. 17. An absorption refrigerating apparatus comprising a generator charged with a refrigerant and an absorbent therefor, means for heat,- ing said generator to evolve refrigerant vapor from the absorbent, means for liquefying said refrigerant vapor, means including a vapor lift pump for utilizing refrigerant vapor flowing from said generator to said liquefying means for rais ing the liquefied refrigerant to a higher level and means for leading vapor from said vapor lift pump to said liquefying means.

18. That method of operating anabsorption refrigerating apparatus which comprises, evolving refrigerant vapor from absorbent at one level,

'fiowing said vapor to a place of condensation at another level, liquefying the refrigerant vapor oration, absorbing the evaporated refrigerant into the-absorbent in the place of evolution and controlling the reversal from evolution to absorption by the temperature of the place of evolution.

19. That method of operating an absorption refrigerating apparatus of the type having two places of evolution and absorption, two places of condensation and two places of evaporation which comprises, evolving refrigerant vapor from an absorbent in one place of evolution and absorption, passing the refrigerant vapor to the first place of condensation, liquefying the vapor in the first place of condensation, utilizing the buoyancy of the vapor fiowing to the first place of condensation for raising liquid refrigerant from the first place of condensation into the first place of evaporation, evaporating the liquid re- .frigerant in said first place of evaporation, ab-

sorbing the vapor into the absorbent in the first place of evolution and absorption, said evaporation step being carried out while evolution and liquefaction is taking place in the-second places of evolution and absorption, and condensation,

and controlling the reversal of evolution and absorption by the temperature of the place of evolution and absorption in which evolution is taking place.

20. That method of operating an absorption refrigerating apparatus which comprises, evolving refrigerant vapor from an absorbent by the application of heat, flowing vapor thus evolved,

to a place of condensation, liquefying the vapor in'the place of condensation, utilizing the buoyancy of the evolved refrigerant vapor for raising the liquefied refrigerant to a place for the separation of liquid and vapor, separating the liquid the flow of refrigerant vapor to the place of evap- 5 oration.

CURTIS czcoons. 

